Backup and Restore Custom Resources

This document describes the fields in the Backup, Restore, and BackupSchedule custom resources (CR). You can use these fields to better perform the backup or restore of TiDB clusters on Kubernetes.

Backup CR fields

To back up data for a TiDB cluster on Kubernetes, you can create a Backup custom resource (CR) object. For detailed backup process, refer to documents listed in Back up data.

This section introduces the fields in the Backup CR.

General fields

.spec.metadata.namespace: the namespace where the Backup CR is located.
.spec.toolImage: the tool image used by Backup. TiDB Operator supports this configuration item starting from v1.1.9.
- When using BR for backup, you can specify the BR version in this field.
  - If the field is not specified or the value is empty, the pingcap/br:${tikv_version} image is used for backup by default.
  - If the BR version is specified in this field, such as .spec.toolImage: pingcap/br:v8.1.0, the image of the specified version is used for backup.
  - If an image is specified without the version, such as .spec.toolImage: private/registry/br, the private/registry/br:${tikv_version} image is used for backup.
- When using Dumpling for backup, you can specify the Dumpling version in this field.
  - If the Dumpling version is specified in this field, such as spec.toolImage: pingcap/dumpling:v8.1.0, the image of the specified version is used for backup.
  - If the field is not specified, the Dumpling version specified in TOOLKIT_VERSION of the Backup Manager Dockerfile is used for backup by default.
.spec.backupType: the backup type. This field is valid only when you use BR for backup. Currently, the following three types are supported, and this field can be combined with the .spec.tableFilter field to configure table filter rules:
- full: back up all databases in a TiDB cluster.
- db: back up a specified database in a TiDB cluster.
- table: back up a specified table in a TiDB cluster.
.spec.backupMode: the backup mode. The default value is snapshot, which means backing up data through the snapshots in the KV layer. This field is valid only for backup and has three value options currently:
- snapshot: back up data through snapshots in the KV layer.
- volume-snapshot: back up data by volume snapshots.
- log: back up log data in real time in the KV layer.
.spec.restoreMode: the restore mode. The default value is snapshot, which means restoring data from snapshots in the KV layer. This field is valid only for restore and has three value options currently:
- snapshot: restore data from snapshots in the KV layer.
- volume-snapshot: restore data from volume snapshots.
- pitr: restore cluster data to a specific point in time based on snapshots and log data.
.spec.tikvGCLifeTime: The temporary tikv_gc_life_time time setting during the backup, which defaults to 72h.
Before the backup begins, if the tikv_gc_life_time setting in the TiDB cluster is smaller than spec.tikvGCLifeTime set by the user, TiDB Operator adjusts the value of tikv_gc_life_time to the value of spec.tikvGCLifeTime. This operation makes sure that the backup data is not garbage-collected by TiKV.
After the backup, whether the backup is successful or not, as long as the previous tikv_gc_life_time value is smaller than .spec.tikvGCLifeTime, TiDB Operator tries to set tikv_gc_life_time to the previous value.
In extreme cases, if TiDB Operator fails to access the database, TiDB Operator cannot automatically recover the value of tikv_gc_life_time and treats the backup as failed.
In such cases, you can view tikv_gc_life_time of the current TiDB cluster using the following statement:
```
SELECT VARIABLE_NAME, VARIABLE_VALUE FROM mysql.tidb WHERE VARIABLE_NAME LIKE "tikv_gc_life_time";
```
In the output of the command above, if the value of tikv_gc_life_time is still larger than expected (usually 10m), you need to manually set tikv_gc_life_time back to the previous value.
.spec.cleanPolicy: The cleaning policy for the backup data when the backup CR is deleted. You can choose one from the following three clean policies:
- Retain: under any circumstances, retain the backup data when deleting the backup CR.
- Delete: under any circumstances, delete the backup data when deleting the backup CR.
- OnFailure: if the backup fails, delete the backup data when deleting the backup CR.
  If this field is not configured, or if you configure a value other than the three policies above, the backup data is retained.
  Note that in v1.1.2 and earlier versions, this field does not exist. The backup data is deleted along with the CR by default. For v1.1.3 or later versions, if you want to keep this earlier behavior, set this field to Delete.
.spec.cleanOption: the clean behavior for the backup files when the backup CR is deleted after the cluster backup. For details, refer to Clean backup data
.spec.from.host: the address of the TiDB cluster to be backed up, which is the service name of the TiDB cluster to be exported, such as basic-tidb.
.spec.from.port: the port of the TiDB cluster to be backed up.
.spec.from.user: the user of the TiDB cluster to be backed up.
.spec.from.secretName: the secret that contains the password of the .spec.from.user.
.spec.from.tlsClientSecretName: the secret of the certificate used during the backup.
If TLS is enabled for the TiDB cluster, but you do not want to back up data using the ${cluster_name}-cluster-client-secret created when you enable TLS between TiDB components, you can use the .spec.from.tlsClient.tlsSecret parameter to specify a secret for the backup. To generate the secret, run the following command:
```
kubectl create secret generic ${secret_name} --namespace=${namespace} --from-file=tls.crt=${cert_path} --from-file=tls.key=${key_path} --from-file=ca.crt=${ca_path}
```
.spec.storageClassName: the persistent volume (PV) type specified for the backup operation.
.spec.storageSize: the PV size specified for the backup operation (100 GiB by default). This value must be greater than the size of the TiDB cluster to be backed up.
The PVC name corresponding to the Backup CR of a TiDB cluster is fixed. If the PVC already exists in the cluster namespace and the size is smaller than spec.storageSize, you need to first delete this PVC and then run the Backup job.
.spec.resources: the resource requests and limits for the Pod that runs the backup job.
.spec.env: the environment variables for the Pod that runs the backup job.
.spec.affinity: the affinity configuration for the Pod that runs the backup job. For details on affinity, refer to Affinity and anti-affinity.
.spec.tolerations: specifies that the Pod that runs the backup job can schedule onto nodes with matching taints. For details on taints and tolerations, refer to Taints and Tolerations.
.spec.podSecurityContext: the security context configuration for the Pod that runs the backup job, which allows the Pod to run as a non-root user. For details on podSecurityContext, refer to Run Containers as a Non-root User.
.spec.priorityClassName: the name of the priority class for the Pod that runs the backup job, which sets priority for the Pod. For details on priority classes, refer to Pod Priority and Preemption.
.spec.imagePullSecrets: the imagePullSecrets for the Pod that runs the backup job.
.spec.serviceAccount: the name of the ServiceAccount used for the backup.
.spec.useKMS: whether to use AWS-KMS to decrypt the S3 storage key used for the backup.
.spec.tableFilter: specifies tables that match the table filter rules for BR or Dumpling. This field can be ignored by default.
When the field is not configured, if you use Dumpling, the default value of tableFilter is as follows:
```
tableFilter:
- "*.*"
- "!/^(mysql|test|INFORMATION_SCHEMA|PERFORMANCE_SCHEMA|METRICS_SCHEMA|INSPECTION_SCHEMA)$/.*"
```
When the field is not configured, if you use BR, BR backs up all schemas except the system schema.
Note
If you want to back up all tables except db.table using the "!db.table" rule, you need to first add the *.* rule to include all tables. For example:
```
tableFilter:
- "*.*"
- "!db.table"
```
.spec.backoffRetryPolicy: the retry policy for abnormal failures (such as Kubernetes killing the node due to insufficient resources) of the Job/Pod during the backup. This configuration currently only takes effect on the snapshot backup.
- minRetryDuration: the minimum retry interval after an abnormal failure is found. The retry interval increases with the number of failures. RetryDuration = minRetryDuration << (retryNum -1). The time format is specified in func ParseDuration, and the default value is 300s.
- maxRetryTimes: the maximum number of retries. The default value is 2.
- retryTimeout: the retry timeout. The timeout starts from the first abnormal failure. The time format is specified in func ParseDuration, and the default value is 30m.

BR fields

.spec.br.cluster: the name of the cluster to be backed up.
.spec.br.clusterNamespace: the namespace of the cluster to be backed up.
.spec.br.logLevel: the log level (info by default).
.spec.br.statusAddr: the listening address through which BR provides statistics. If not specified, BR does not listen on any status address by default.
.spec.br.concurrency: the number of threads used by each TiKV process during backup. Defaults to 4 for backup and 128 for restore.
.spec.br.rateLimit: the speed limit, in MB/s. If set to 4, the speed limit is 4 MB/s. The speed limit is not set by default.
.spec.br.checksum: whether to verify the files after the backup is completed. Defaults to true.
.spec.br.timeAgo: backs up the data before timeAgo. If the parameter value is not specified (empty by default), it means backing up the current data. It supports data formats such as "1.5h" and "2h45m". See ParseDuration for more information.
.spec.br.sendCredToTikv: whether the BR process passes its AWS, Google Cloud, or Azure permissions to the TiKV process. Defaults to true.
.spec.br.onLine: whether to enable the online restore feature when restoring data.
.spec.br.options: the extra arguments that BR supports. This field is supported since TiDB Operator v1.1.6. It accepts an array of strings and can be used to specify the last backup timestamp --lastbackupts for incremental backup.

S3 storage fields

.spec.s3.provider: the supported S3-compatible storage provider. All supported providers are as follows:
- alibaba: Alibaba Cloud Object Storage System (OSS), formerly Aliyun
- digitalocean: Digital Ocean Spaces
- dreamhost: Dreamhost DreamObjects
- ibmcos: IBM COS S3
- minio: Minio Object Storage
- netease: Netease Object Storage (NOS)
- wasabi: Wasabi Object Storage
- other: any other S3 compatible provider
spec.s3.region: if you want to use Amazon S3 for backup storage, configure this field as the region where Amazon S3 is located.
.spec.s3.bucket: the name of the bucket of the S3-compatible storage.
.spec.s3.prefix: if you set this field, the value is used to make up the remote storage path s3://${.spec.s3.bucket}/${.spec.s3.prefix}/backupName.
.spec.s3.path: specifies the storage path of backup files on the remote storage. This field is valid only when the data is backed up using Dumpling or restored using TiDB Lightning. For example, s3://test1-demo1/backup-2019-12-11T04:32:12Z.tgz.
.spec.s3.endpoint：the endpoint of S3 compatible storage service, for example, http://minio.minio.svc.cluster.local:9000.
.spec.s3.secretName：the name of secret which stores S3 compatible storage's access key and secret key.
.spec.s3.sse: specifies the S3 server-side encryption method. For example, aws:kms.
.spec.s3.acl: the supported access-control list (ACL) policies.
Amazon S3 supports the following ACL options:
- private
- public-read
- public-read-write
- authenticated-read
- bucket-owner-read
- bucket-owner-full-control
  If the field is not configured, the policy defaults to private. For more information on the ACL policies, refer to AWS documentation.
.spec.s3.storageClass: the supported storage class.
Amazon S3 supports the following storage class options:
- STANDARD
- REDUCED_REDUNDANCY
- STANDARD_IA
- ONEZONE_IA
- GLACIER
- DEEP_ARCHIVE
  If the field is not configured, the storage class defaults to STANDARD_IA. For more information on storage classes, refer to AWS documentation.

GCS fields

.spec.gcs.projectId: the unique identifier of the user project on Google Cloud. To obtain the project ID, refer to Google Cloud documentation.
.spec.gcs.location: the location of the GCS bucket. For example, us-west2.
.spec.gcs.path: the storage path of backup files on the remote storage. This field is valid only when the data is backed up using Dumpling or restored using TiDB Dumpling. For example, gcs://test1-demo1/backup-2019-11-11T16:06:05Z.tgz.
.spec.gcs.secretName: the name of the secret that stores the GCS account credential.
.spec.gcs.bucket: the name of the bucket which stores data.
.spec.gcs.prefix: if you set this field, the value is used to make up the path of the remote storage: gcs://${.spec.gcs.bucket}/${.spec.gcs.prefix}/backupName.
.spec.gcs.storageClass: the supported storage class.
GCS supports the following storage class options:
- MULTI_REGIONAL
- REGIONAL
- NEARLINE
- COLDLINE
- DURABLE_REDUCED_AVAILABILITY
  If the field is not configured, the storage class defaults to COLDLINE. For more information on storage classes, refer to GCS documentation.
.spec.gcs.objectAcl: the supported object access-control list (ACL) policies.
GCS supports the following object ACL options:
- authenticatedRead
- bucketOwnerFullControl
- bucketOwnerRead
- private
- projectPrivate
- publicRead
  If the field is not configured, the policy defaults to private. For more information on the ACL policies, refer to GCS documentation.
.spec.gcs.bucketAcl: the supported bucket access-control list (ACL) policies.
GCS supports the following bucket ACL options:
- authenticatedRead
- private
- projectPrivate
- publicRead
- publicReadWrite
  If the field is not configured, the policy defaults to private. For more information on the ACL policies, refer to GCS documentation.

Azure Blob Storage fields

.spec.azblob.secretName: the name of the secret which stores Azure Blob Storage account credential.
.spec.azblob.container: the name of the container which stores data.
.spec.azblob.prefix: if you set this field, the value is used to make up the remote storage path azure://${.spec.azblob.container}/${.spec.azblob.prefix}/backupName.
.spec.azblob.accessTier: the access tier of the uploaded data.
Azure Blob Storage supports the following access tier options:
- Hot
- Cool
- Archive
If this field is not configured, Cool is used by default.

Local storage fields

.spec.local.prefix: the storage directory of the persistent volumes. If you set this field, the value is used to make up the storage path of the persistent volume: local://${.spec.local.volumeMount.mountPath}/${.spec.local.prefix}/.
.spec.local.volume: the persistent volume configuration.
.spec.local.volumeMount: the persistent volume mount configuration.

Restore CR fields

To restore data to a TiDB cluster on Kubernetes, you can create a Restore CR object. For detailed restore process, refer to documents listed in Restore data.

This section introduces the fields in the Restore CR.

.spec.metadata.namespace: the namespace where the Restore CR is located.
.spec.toolImage：the tools image used by Restore. TiDB Operator supports this configuration starting from v1.1.9.
- When using BR for restoring, you can specify the BR version in this field. For example,spec.toolImage: pingcap/br:v8.1.0. If not specified, pingcap/br:${tikv_version} is used for restoring by default.
- When using Lightning for restoring, you can specify the Lightning version in this field. For example, spec.toolImage: pingcap/lightning:v8.1.0. If not specified, the Lightning version specified in TOOLKIT_VERSION of the Backup Manager Dockerfile is used for restoring by default.
.spec.backupType: the restore type. This field is valid only when you use BR to restore data. Currently, the following three types are supported, and this field can be combined with the .spec.tableFilter field to configure table filter rules:
- full: restore all databases in a TiDB cluster.
- db: restore a specified database in a TiDB cluster.
- table: restore a specified table in a TiDB cluster.
.spec.tikvGCLifeTime: the temporary tikv_gc_life_time setting during the restore, which defaults to 72h.
Before the restore begins, if the tikv_gc_life_time setting in the TiDB cluster is smaller than spec.tikvGCLifeTime set by users, TiDB Operator adjusts the value of tikv_gc_life_time to the value of spec.tikvGCLifeTime. This operation makes sure that the restored data is not garbage-collected by TiKV.
After the restore, whether the restore is successful or not, as long as the original tikv_gc_life_time value is smaller than .spec.tikvGCLifeTime, TiDB Operator tries to set tikv_gc_life_time back to the original value.
In extreme cases, if TiDB Operator fails to access the database, TiDB Operator cannot automatically recover the value of tikv_gc_life_time and treats the restore as failed.
In such cases, you can view tikv_gc_life_time of the current TiDB cluster using the following statement:
```
SELECT VARIABLE_NAME, VARIABLE_VALUE FROM mysql.tidb WHERE VARIABLE_NAME LIKE "tikv_gc_life_time";
```
In the output of the command above, if the value of tikv_gc_life_time is still larger than expected (usually 10m), you need to manually set tikv_gc_life_time back to the previous value.
.spec.to.host: the address of the TiDB cluster to be restored.
.spec.to.port: the port of the TiDB cluster to be restored.
.spec.to.user: the user of the TiDB cluster to be restored.
.spec.to.secretName: the secret that contains the password of the .spec.to.user.
.spec.to.tlsClientSecretName: the secret of the certificate used during the restore.
If TLS is enabled for the TiDB cluster, but you do not want to restore data using the ${cluster_name}-cluster-client-secret created when you enable TLS between TiDB components, you can use the .spec.to.tlsClient.tlsSecret parameter to specify a secret for the restore. To generate the secret, run the following command:
```
kubectl create secret generic ${secret_name} --namespace=${namespace} --from-file=tls.crt=${cert_path} --from-file=tls.key=${key_path} --from-file=ca.crt=${ca_path}
```
.spec.resources: the resource requests and limits for the Pod that runs the restore job.
.spec.env: the environment variables for the Pod that runs the restore job.
.spec.affinity: the affinity configuration for the Pod that runs the restore job. For details on affinity, refer to Affinity and anti-affinity.
.spec.tolerations: specifies that the Pod that runs the restore job can schedule onto nodes with matching taints. For details on taints and tolerations, refer to Taints and Tolerations.
.spec.podSecurityContext: the security context configuration for the Pod that runs the restore job, which allows the Pod to run as a non-root user. For details on podSecurityContext, refer to Run Containers as a Non-root User.
.spec.priorityClassName: the name of the priority class for the Pod that runs the restore job, which sets priority for the Pod. For details on priority classes, refer to Pod Priority and Preemption.
.spec.imagePullSecrets: the imagePullSecrets for the Pod that runs the restore job.
.spec.serviceAccount: the name of the ServiceAccount used for restore.
.spec.useKMS: whether to use AWS-KMS to decrypt the S3 storage key used for the backup.
.spec.storageClassName: the persistent volume (PV) type specified for the restore operation.
.spec.storageSize: the PV size specified for the restore operation. This value must be greater than the size of the backup data.
.spec.tableFilter: specifies tables that match the table filter rules for BR. This field can be ignored by default.
When the field is not configured, if you use TiDB Lightning, the default tableFilter value for TiDB Lightning is as follows:
```
tableFilter:
- "*.*"
- "!/^(mysql|test|INFORMATION_SCHEMA|PERFORMANCE_SCHEMA|METRICS_SCHEMA|INSPECTION_SCHEMA)$/.*"
```
When the field is not configured, if you use BR, BR restores all the schemas in the backup file.
Note
If you want to backup up all table except db.table using the "!db.table" rule, you need to first add the *.* rule to include all tables. For example:
```
tableFilter:
- "*.*"
- "!db.table"
```
.spec.br: BR-related configuration. Refer to BR fields.
.spec.s3: S3-related configuration. Refer to S3 storage fields.
.spec.gcs: GCS-related configuration. Refer to GCS fields.
.spec.azblob：Azure Blob Storage-related configuration. Refer to Azure Blob Storage fields.
.spec.local: persistent volume-related configuration. Refer to Local storage fields.

BackupSchedule CR fields

The backupSchedule configuration consists of three parts: the configuration of the snapshot backup backupTemplate, the configuration of the log backup logBackupTemplate, and the unique configuration of backupSchedule.

backupTemplate: the configuration of the snapshot backup. Specifies the configuration related to the cluster and remote storage of the snapshot backup, which is the same as the spec configuration of the Backup CR.
logBackupTemplate: the configuration of the log backup. Specifies the configuration related to the cluster and remote storage of the log backup, which is the same as the spec configuration of the Backup CR. The log backup is created and deleted along with backupSchedule and recycled according to .spec.maxReservedTime. The log backup name is saved in status.logBackup.
Note
Before you delete the log backup data, you need to stop the log backup task to avoid resource waste or the inability to restart the log backup task in the future because the log backup task in TiKV is not stopped.
The unique configuration items of backupSchedule are as follows:
- .spec.maxBackups: a backup retention policy, which determines the maximum number of backup files to be retained. When the number of backup files exceeds this value, the outdated backup file will be deleted. If you set this field to 0, all backup items are retained.
- .spec.maxReservedTime: a backup retention policy based on time. For example, if you set the value of this field to 24h, only backup files within the recent 24 hours are retained. All backup files older than this value are deleted. For the time format, refer to func ParseDuration. If you have set .spec.maxBackups and .spec.maxReservedTime at the same time, the latter takes effect.
- .spec.schedule: the time scheduling format of Cron. Refer to Cron for details.
- .spec.pause: false by default. If this field is set to true, the scheduled scheduling is paused. In this situation, the backup operation will not be performed even if the scheduling time point is reached. During this pause, the backup garbage collection runs normally. If you change true to false, the scheduled snapshot backup process is restarted. Because currently, log backup does not support pause, this configuration does not take effect for log backup.